<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <button class="bbb">dw</button>
    <script>
        let btn = document.querySelector('.bbb');
        // btn.onclick = function() {
        //     console.log(11111);
        // }
        // btn.onclick = function() {
        //     console.log(222222);
        // }

        btn.addEventListener('click', function() {
            console.log(111);
        }, false)
        btn.addEventListener('click', function() {
            console.log(222);
        })
    </script>
</body>

</html>